AssayIndex

AX-2025-020063

P21 · 5 mg declared · Shanghai Wibson Biotechnology Co., Ltd. · lot SWB-2408-T8372

PASSIDENTITY CONSISTENT
Report ID
AX-2025-020063
Compound
P21
Compound class
Neuroactive and cognitive peptides
Supplier
SWB — Shanghai Wibson Biotechnology Co., Ltd.
Batch / lot
SWB-2408-T8372
Declared label claim
5mg
Laboratory
Kestrel Bioanalytical
Assay date
26 Mar 2025
Submitted
11 Apr 2025
Quarter
2025-Q1
Submitter
p.kjaer
Sample provenance
Buyer-sourced
Section 1

Results

Measured against the index acceptance specification for the neuroactive and cognitive peptides class. A specification is a decision the index made; a result is a measurement. See where each threshold came from.

ParameterMethodResultUnitIndex spec
PurityRP-HPLC, 15 min gradient, 214 nm99.02% area≥ 98.0PASS
Total impuritiesRP-HPLC, sum of reported peaks0.98% area≤ 2.0PASS
Largest single impurityRP-HPLC — aspartimide (−18 Da)0.55% area≤ 1.00PASS
Identity — theoretical monoisotopic masscalculated from molecular formula805.3970DaNOT TESTED
Identity — observed monoisotopic massLC-MS, unit resolution (single quadrupole)805.4005DaNOT TESTED
Mass accuracyobserved vs theoretical+4.3ppm± 15PASS
Total peptide contentby difference from the gravimetric mass balance84.78%w/wNOT TESTED
Target-compound contenttotal peptide content × purity83.95%w/wNOT TESTED
Gross fill (as weighed)five-place balance, under nitrogen5.87mg5 mg declaredNOT TESTED
Recovered target peptidegross fill × target content4.928mg5 mg claimNOT TESTED
Recovery against label claimrecovered ÷ claim98.6%90.0 – 110.0PASS
Water contentKarl Fischer, coulometric, duplicate8.23%≤ 12.0PASS
Counter-ion (acetate)anion-exchange ion chromatography6.79%≤ 10.0PASS
Residual solvent + inorganic residueestimated — see /methods/residual-solvents-q3c/0.20%NOT TESTED
Endotoxinnot ordered on this submissionnot determined≤ 5.0NOT TESTED
Sterilitynot ordered on this submissionnot determinedno growthNOT TESTED
Appearancevisual, diffuse light, black and white backgroundWhite lyophilised cake, intactwhite to off-white intact cakePASS
Reconstitution clarityreconstituted per submitter procedureClear after 90 s gentle swirling, no particulatesclear, no visible particulatesPASS
pH (reconstituted, 1 mg/mL)potentiometric, two-point calibration4.902.5 – 8.0PASS
Retention time (observed)RP-HPLC, 15 min gradient5.64min5.63 ± 0.30 (normalised)PASS
Peak asymmetry (10 % height)Ph. Eur. 2.2.461.110.80 – 1.50PASS
Plate count, main peakN = 5.54 (t/w½)²60,037≥ 20,000PASS
Resolution to nearest impurityvs free acid (+1 Da)1.17no index criterionREPORTED
Section 2

Chromatogram and peak integration

The figure is drawn from the table. It is not an independent illustration — if a number in the table changed, the trace would change with it.

0472094401416018880 P215.64 min · 99.02 % 5.794.61 same trace · ×100 vertical expansion, baseline-corrected · main peak off-scale reporting threshold 0.05 % area 048121620 Retention time (min) Response (mAU)
Figure 1. RP-HPLC trace, 15 min gradient, 214 nm. Drawn from the peak-integration table below: peak positions are the reported retention times, peak areas are the reported area percentages, peak widths follow the reported plate count of 60,037, and skew follows the reported asymmetry factor of 1.11. Baseline noise is seeded from the report ID and is illustrative. The lower panel is the same trace at a stated vertical expansion with the slow gradient drift subtracted, because at full scale a 0.55 % impurity against a 99.02 % main peak is a line two pixels tall; the main peak runs off-scale there by design.
#PeakRTArea (µV·s)% areaΔ mass (Da)
1P21 — main peak5.644,812,67999.02
2aspartimide (−18 Da)5.7926,7320.55-18.011
3des-adamantyl (−134 Da)4.6114,0950.29-134.110
4des-acetyl (−42 Da)5.433,8880.08-42.011
5free acid (+1 Da)5.752,9160.06+0.984
Closure check — purity + Σ impurities 100.00CLOSES

Reporting threshold 0.05 % area. Peaks below it are not reported and are therefore excluded from the total, which overstates purity by their sum — see peak integration.

Section 3

Mass spectrum and identity

Theoretical monoisotopic mass 805.3970 Da, computed from C36H55N9O12. All ppm figures on this site are against monoisotopic values — see why that matters.

0255075100350450550650750850 [M+1H]1+806.41[M+2H]2+403.71 m/z Relative abundance (%)
Figure 2. ESI charge-state envelope, unit-resolution instrument. Sticks are placed at m/z = (M + z × 1.007276)/z for the observed neutral mass of 805.4005 Da. Sodium (+21.982/z) and potassium (+37.956/z) adducts are shown where the parent charge state exceeds 25 % relative abundance; they are adducts of the same molecule and are not impurities.
ChargeTheoretical m/zObserved m/zΔ m/zRel. abundance (%)
2+403.7058403.70750.001755.6
1+806.4043806.40780.0035100.0
Section 4

Gravimetric mass balance

Water, counter-ion, residual and total peptide content are exhaustive and mutually exclusive categories. They must account for 100 % of the cake mass. The index closes this to within 0.02 pp and the build asserts it.

ComponentDetermination%w/w of cake
WaterKarl Fischer8.23
Counter-ion (acetate)ion chromatography6.79
Residual solvent + inorganic residueestimated0.20
Total peptide contentby difference84.78
Total100.00 CLOSES

Supplier certificate, as declared

The supplier's own figures for this lot, beside the independent measurement. Divergence is assessed against the batch median, not against this single report — see rule AX-R05.

FigureSupplier COAThis reportIndex note
Purity (% area)99.2299.02divergence -0.02 pp vs batch median
Total impurities (% area)0.780.98
Largest single impurity (% area)0.510.55
Water (%)not stated8.23
Counter-ion (%)not stated6.79
Peptide content (%w/w)not stated84.78
Endotoxin (EU/mg)not statednot determined
Method stated on certificateYEScolumn, gradient and wavelength given
Section 5

Provenance and caveats

Where a sample came from changes the weight of the evidence. The index treats it as a first-class field.

Sample provenance
Buyer-sourced
Evidentiary weight
Strongest available evidence in this index.
Chain of custody
Domestic warehouse despatch → submitter (2–8 °C, 3 d) → laboratory (courier, cold pack, 4 d) → assay.
Assay date
26 Mar 2025
Submitted to the index
11 Apr 2025
Laboratory
Kestrel Bioanalytical, Melbourne, Australia
Method basis
15 min gradient · unit-resolution MS
Verification status
IDENTITY CONSISTENT
Section 6

Annotations 2

Signed technical comments from index contributors. Not a discussion forum — annotations question or contextualise the result, and the data team replies where a reply is warranted.

ppm_error
Instrument was evidently in calibration on the day. A run of results at this accuracy across a laboratory's sequence is the background against which an excursion becomes interpretable.
buyer_sourced
Independently purchased, at the submitter's own cost, forwarded without the supplier's involvement. That is the definition and this record meets it.
Section 7

Related records

Same batch — lot SWB-2408-T8372 n=8

ReportLotLabQuarterPurity %Water %Recovery %ProvenanceFlagsResult
AX-2025-020062SWB-2408-T8372Janoshik2025-Q199.228.2890.7Buyer-sourced0PASS
AX-2025-020064SWB-2408-T8372Janoshik2025-Q199.258.45Buyer-sourced0PASS
AX-2025-020065SWB-2408-T8372Janoshik2025-Q199.748.5698.6Buyer-sourced0PASS
AX-2025-020066SWB-2408-T8372Janoshik2025-Q198.767.3594.7Buyer-sourced0PASS
AX-2025-020067SWB-2408-T8372VendorInvestigate2025-Q199.058.58106.1Buyer-sourced0PASS
AX-2025-020068SWB-2408-T8372Nordanalyt2025-Q199.528.16Buyer-sourced0PASS
AX-2025-020069SWB-2408-T8372Medutest2025-Q199.408.62103.6Buyer-sourced0PASS
Other recent P21 records in the index.
ReportSupplierLotLabQuarterPurity %Water %Recovery %ProvenanceFlagsResult
AX-2025-020065SWBSWB-2408-T8372Janoshik2025-Q199.748.5698.6Buyer-sourced0PASS
AX-2025-020069SWBSWB-2408-T8372Medutest2025-Q199.408.62103.6Buyer-sourced0PASS
AX-2025-020066SWBSWB-2408-T8372Janoshik2025-Q198.767.3594.7Buyer-sourced0PASS
AX-2025-020067SWBSWB-2408-T8372VendorInvestigate2025-Q199.058.58106.1Buyer-sourced0PASS
AX-2025-020068SWBSWB-2408-T8372Nordanalyt2025-Q199.528.16Buyer-sourced0PASS
AX-2025-020062SWBSWB-2408-T8372Janoshik2025-Q199.228.2890.7Buyer-sourced0PASS
AX-2025-020064SWBSWB-2408-T8372Janoshik2025-Q199.258.45Buyer-sourced0PASS
Other recent SWB records in the index.
ReportCompoundLotLabQuarterPurity %Water %Recovery %ProvenanceFlagsResult
AX-2026-042637SemaglutideSWB-2602-X7905Janoshik2026-Q398.374.26102.9Buyer-sourced0PASS
AX-2026-042645SemaglutideSWB-2602-X7905Medutest2026-Q398.484.5295.2Buyer-sourced0PASS
AX-2026-042642SemaglutideSWB-2602-X7905PeptideMeter2026-Q397.964.4890.8Buyer-sourced0PASS
AX-2026-042640SemaglutideSWB-2602-X7905PeptideMeter2026-Q398.554.29Buyer-sourced0PASS
AX-2026-042638SemaglutideSWB-2602-X7905Janoshik2026-Q398.743.65Buyer-sourced0PASS
AX-2026-042639SemaglutideSWB-2602-X7905Janoshik2026-Q398.774.21Supplier-supplied0PASS
AX-2026-042641SemaglutideSWB-2602-X7905Janoshik2026-Q398.864.4899.1Buyer-sourced0PASS
AX-2026-042644SemaglutideSWB-2602-X7905PeptideMeter2026-Q398.763.5797.7Buyer-sourced0PASS